Rigid foam and associated article and method

ABSTRACT

A rigid polyurethane or polyisocyanurate foam includes 1 to 50 weight percent of a particulate poly(phenylene ether) having a mean particle size of 1 to 40 micrometers. The particulate poly(phenylene ether) imparts reduced flammability and reduced water absorption to the foam. The foam is useful as a thermally insulating material in articles including domestic appliances, building materials, tanks, pipelines, heating pipes, cooling pipes, cold stores, and refrigerated vehicles.

BACKGROUND OF THE INVENTION

Polyurethanes are prepared from compounds with at least two hydroxylgroups and compounds with at least two isocyanate groups. See, e.g., D.Randall and S. Lee, “The Polyurethanes Book”, New York: John Wiley &Sons, 2003; and K. Uhlig, “Discovering Polyurethanes”, New York: HanserGardner, 1999. The isocyanate groups of the isocyanate compound reactwith the hydroxyl groups of the hydroxyl compound to form urethanelinkages. In many cases, the hydroxyl compound is a low molecular weightpolyether or polyester. The isocyanate compound can be aliphatic oraromatic, and in the preparation of linear polyurethanes is typicallydifunctional (i.e., it is a diisocyanate). However isocyanate compoundswith greater functionality are used in preparing thermosetpolyurethanes. The family of polyurethane resins is very complex becauseof the enormous variation in the compositional features of the hydroxylcompounds and isocyanate compounds. This variety results in a largenumbers of polymer structures and performance profiles. Indeed,polyurethanes can be rigid solids, soft and elastomeric, or a have afoam (cellular) structure.

Rigid polyurethane and polyisocyanurate foams are particularly effectivethermal insulators. Most applications are as insulating materials inconstruction. However, the inherent ability of polyurethane andpolyisocyanurate foams to burn creates a need for reduced flammability.See, e.g., S. V. Levchik, E. D. Weil, “Thermal decomposition, combustionand fire-retardancy of polyurethanes—a review of the recent literature”,Polymer International, volume 53, pages 1585-1610 (2004). Polyurethaneand polyisocyanurate foams also exhibit high moisture absorption, withthe absorbed moisture acting as a plasticizer that detracts from thephysical properties of the foams.

There is therefore a need for polyurethane and polyisocyanurate foamsexhibiting improved resistance to burning and/or reduced moistureabsorption.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

One embodiment is a polyurethane or polyisocyanurate foam comprising 1to 50 weight percent, based on the total weight of the polyurethane orpolyisocyanurate foam, of a particulate poly(phenylene ether) having amean particle size of 1 to 40 micrometers; wherein the polyurethane orpolyisocyanurate foam has a core density of 0.03 to 0.7grams/centimeter³ determined at 23° C. using ASTM D 1622-03.

Another embodiment is an article comprising thermal insulationcomprising polyurethane or polyisocyanurate foam comprising 1 to 50weight percent, based on the total weight of the polyurethane orpolyisocyanurate foam, of a particulate poly(phenylene ether) having amean particle size of 1 to 40 micrometers; wherein the polyurethane orpolyisocyanurate foam has a core density of 0.03 to 0.7grams/centimeter³ determined at 23° C. using ASTM D 1622-03.

Another embodiment is a method of forming a polyurethane orpolyisocyanurate foam, the method comprising: reacting a polyol and anisocyanate compound in the presence of a blowing agent and a particulatepoly(phenylene ether) to form a polyurethane or polyisocyanurate foam;wherein the isocyanate compound comprises, on average, at least twoisocyanate groups per molecule; wherein the particulate poly(phenyleneether) has a mean particle size of 1 to 40 micrometers; and wherein thepolyurethane or polyisocyanurate foam comprises 1 to 50 weight percentof the particulate poly(phenylene ether).

These and other embodiments are described in detail below.

DETAILED DESCRIPTION OF THE INVENTION

The present inventor has determined that rigid polyurethane andpolyisocyanurate foams exhibiting improved resistance to burning and/orreduced moisture absorption are obtained by incorporating particulatepoly(phenylene ether) into the foams.

One embodiment is a polyurethane or polyisocyanurate foam comprising 1to 50 weight percent, based on the total weight of the polyurethane orpolyisocyanurate foam, of a particulate poly(phenylene ether) having amean particle size of 1 to 40 micrometers; wherein the polyurethane orpolyisocyanurate foam has a core density of 0.03 to 0.7grams/centimeter³ determined at 23° C. using ASTM D 1622-03.

The polyurethane or polyisocyanurate foam comprises a particulatepoly(phenylene ether). Poly(phenylene ether)s include those comprisingrepeating structural units having the formula

wherein each occurrence of Z¹ is independently halogen, unsubstituted orsubstituted C₁-C₁₂ hydrocarbyl provided that the hydrocarbyl group isnot tertiary hydrocarbyl, C₁-C₁₂ hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy,or C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separatethe halogen and oxygen atoms; and each occurrence of Z² is independentlyhydrogen, halogen, unsubstituted or substituted C₁-C₁₂ hydrocarbylprovided that the hydrocarbyl group is not tertiary hydrocarbyl, C₁-C₁₂hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy, or C₂-C₁₂ halohydrocarbyloxywherein at least two carbon atoms separate the halogen and oxygen atoms.As used herein, the term “hydrocarbyl”, whether used by itself, or as aprefix, suffix, or fragment of another term, refers to a residue thatcontains only carbon and hydrogen. The residue can be aliphatic oraromatic, straight-chain, cyclic, bicyclic, branched, saturated, orunsaturated. It can also contain combinations of aliphatic, aromatic,straight chain, cyclic, bicyclic, branched, saturated, and unsaturatedhydrocarbon moieties. However, when the hydrocarbyl residue is describedas substituted, it may, optionally, contain heteroatoms over and abovethe carbon and hydrogen members of the substituent residue. Thus, whenspecifically described as substituted, the hydrocarbyl residue can alsocontain one or more carbonyl groups, amino groups, hydroxyl groups, orthe like, or it can contain heteroatoms within the backbone of thehydrocarbyl residue. As one example, Z¹ can be a di-n-butylaminomethylgroup formed by reaction of a terminal 3,5-dimethyl-1,4-phenyl groupwith the di-n-butylamine component of an oxidative polymerizationcatalyst.

The poly(phenylene ether) can comprise molecules havingaminoalkyl-containing end group(s), typically located in a positionortho to the hydroxyl group. Also frequently present aretetramethyldiphenoquinone (TMDQ) end groups, typically obtained from2,6-dimethylphenol-containing reaction mixtures in whichtetramethyldiphenoquinone by-product is present. The poly(phenyleneether) can be in the form of a homopolymer, a copolymer, a graftcopolymer, an ionomer, or a block copolymer, as well as combinationsthereof.

In some embodiments, the poly(phenylene ether) comprises apoly(phenylene ether)-polysiloxane block copolymer. As used herein, theterm “poly(phenylene ether)-polysiloxane block copolymer” refers to ablock copolymer comprising at least one poly(phenylene ether) block andat least one polysiloxane block.

In some embodiments, the poly(phenylene ether)-polysiloxane blockcopolymer is prepared by an oxidative copolymerization method. In thismethod, the poly(phenylene ether)-polysiloxane block copolymer is theproduct of a process comprising oxidatively copolymerizing a monomermixture comprising a monohydric phenol and a hydroxyaryl-terminatedpolysiloxane. In some embodiments, the monomer mixture comprises 70 to99 parts by weight of the monohydric phenol and 1 to 30 parts by weightof the hydroxyaryl-terminated polysiloxane, based on the total weight ofthe monohydric phenol and the hydroxyaryl-terminated polysiloxane. Thehydroxyaryl-diterminated polysiloxane can comprise a plurality ofrepeating units having the structure

wherein each occurrence of R⁸ is independently hydrogen, C₁-C₁₂hydrocarbyl or C₁-C₁₂ halohydrocarbyl; and two terminal units having thestructure

wherein Y is hydrogen, C₁-C₁₂ hydrocarbyl, C₁-C₁₂ hydrocarbyloxy, orhalogen, and wherein each occurrence of R⁹ is independently hydrogen,C₁-C₁₂ hydrocarbyl or C₁-C₁₂ halohydrocarbyl. In a very specificembodiment, each occurrence of R⁸ and R⁹ is methyl, and Y is methoxyl.

In some embodiments, the monohydric phenol comprises 2,6-dimethylphenol,2,3,6-trimethylphenol, or a combination thereof, and thehydroxyaryl-terminated polysiloxane has the structure

wherein n is, on average, 5 to 100, specifically 30 to 60.

The oxidative copolymerization method produces poly(phenyleneether)-polysiloxane block copolymer as the desired product andpoly(phenylene ether) (without an incorporated polysiloxane block) as aby-product. It is not necessary to separate the poly(phenylene ether)from the poly(phenylene ether)-polysiloxane block copolymer. Thepoly(phenylene ether)-polysiloxane block copolymer can thus be utilizedas a “reaction product” that includes both the poly(phenylene ether) andthe poly(phenylene ether)-polysiloxane block copolymer. Certainisolation procedures, such as precipitation from isopropanol, make itpossible to assure that the reaction product is essentially free ofresidual hydroxyaryl-terminated polysiloxane starting material. In otherwords, these isolation procedures assure that the polysiloxane contentof the reaction product is essentially all in the form of poly(phenyleneether)-polysiloxane block copolymer. Detailed methods for formingpoly(phenylene ether)-polysiloxane block copolymers are described inU.S. Pat. No. 8,017,697 to Carrillo et al., and U.S. Patent ApplicationPublication No. US 2012/0329961 A1 of Carrillo et al.

In some embodiments, the poly(phenylene ether) has an intrinsicviscosity of 0.25 to 1 deciliter per gram measured by Ubbelohdeviscometer at 25° C. in chloroform. Within this range, thepoly(phenylene ether) intrinsic viscosity can be 0.3 to 0.65 deciliterper gram, more specifically 0.35 to 0.5 deciliter per gram, even morespecifically 0.4 to 0.5 deciliter per gram.

In some embodiments, the poly(phenylene ether) comprises a homopolymeror copolymer of monomers selected from the group consisting of2,6-dimethylphenol, 2,3,6-trimethylphenol, and combinations thereof.

In some embodiments, the poly(phenylene ether) comprises apoly(phenylene ether)-polysiloxane block copolymer. In theseembodiments, the poly(phenylene ether)-polysiloxane block copolymer can,for example, contribute 0.05 to 2 weight percent, specifically 0.1 to 1weight percent, more specifically 0.2 to 0.8 weight percent, of siloxanegroups to the composition as a whole.

The particulate poly(phenylene ether) has a mean particle size of 1 to40 micrometers. Within this range, the mean particle size can be 1 to 20micrometers, specifically 2 to 8 micrometers. In some embodiments, 90percent of the particle volume distribution of the particulatepoly(phenylene ether) is less than or equal to 23 micrometers,specifically less than or equal to 17 micrometers, more specifically 1to 8 micrometers. In some embodiments, fifty percent of the particlevolume distribution of the particulate poly(phenylene ether) is than orequal to 15 micrometers, specifically less than or equal to 10micrometers, more specifically less than or equal to 6 micrometers. Insome embodiments, ten percent of the particle volume distribution of theparticulate poly(phenylene ether) is less than or equal to 9micrometers, specifically less than or equal to 6 micrometers, morespecifically less than or equal to 4 micrometers. In some embodiments,less than 10 percent, specifically less than 1 percent, and morespecifically less than 0.1 percent, of the particle volume distributionis less than or equal to 38 nanometers. In some embodiments, theparticles of the particulate poly(phenylene ether) have a mean aspectratio of 1:1 to 2:1. Equipment to determine particle size and shapecharacteristics is commercially available as, for example, the CAMSIZER™and CAMSIZER™ XT Dynamic Image Analysis Systems from Retsch Technology,and the QICPIC™ Particle Size and Shape Analyzer from Sympatec.

Particulate poly(phenylene ether) can be obtained according to methodsreadily available to the skilled artisan, for example by jet milling,ball milling, pulverizing, air milling, or grinding commercial gradepoly(phenylene ether). “Classification” is defined as the sorting of adistribution of particles to achieve a desired degree of particle sizeuniformity. A classifier is often used together with milling for thecontinuous extraction of fine particles from the material being milled.The classifier can be, for example, a screen of certain mesh size on thewalls of the grinding chamber. Once the milled particles reach sizessmall enough to pass through the screen, they are removed. Largerparticles retained by the screen remain in the milling chamber foradditional milling and size reduction.

Air classification is another method of removing the finer particlesfrom milling. Air classifiers include static classifiers (cyclones),dynamic classifiers (single-stage, multi-stage), cross-flow classifiers,and counter-flow classifiers (elutriators). In general, a flow of air isused to convey the particles from the mill to the classifier, where thefine particles are further conveyed to a collector. The coarseparticles, being too heavy to be carried by the air stream, are returnedto the mill for further milling and size reduction. In largeroperations, air classification is more efficient, while in smalleroperations a screen can be used.

The polyurethane or polyisocyanurate foam comprises the particulatepoly(phenylene ether) in an amount of 1 to 50 weight percent, based onthe total weight of the polyurethane or polyisocyanurate foam (which isequivalent to the total weight of the reaction mixture from which thefoam is prepared). Within this range, the amount of particulatepoly(phenylene ether) can be 3 to 40 weight percent, specifically 5 to30 weight percent.

The polyurethane or polyisocyanurate foam has a core density of 0.03 to0.7 grams/centimeter³ determined at 23° C. using ASTM D 1622-03. Withinthis range, the core density can be 0.03 to 0.2 grams/centimeter³,specifically 0.03 to 0.06 grams/centimeter³.

Those skilled in the art understand that there is a continuum betweenpolyurethane and polyisocyanurate foams. Both are prepared frompolyisocyanates and polyols. Reaction mixtures used to preparepolyurethane and polyisocyanurate foams are characterized by anisocyanate index, which is calculated according to the equation

${{Isocyanate}\mspace{14mu} {Index}} = {\frac{{Moles}_{NCO}}{{Moles}_{OH} + {Moles}_{HOH} + {Moles}_{NH}} \times 100}$

wherein Moles_(NCO) is the moles of isocyanate groups in the reactionmixture, Moles_(OH) is the moles of OH groups in the reaction mixturefrom sources other than water (including OH groups from alcohols andcarboxylic acid), Moles_(HOH) is the moles of OH groups in the reactionmixture from water, and Moles_(NH) is the moles of NH groups in thereaction mixture. When the reaction mixture molar ratio of isocyanategroups to hydroxyl groups is 1:1 and no water or NH groups are presentin the reaction mixture, the isocyanate index is 100, and a “pure”polyurethane is formed. The products of reaction mixtures having anisocyanate index of 100 to 125, specifically 105 to 125, are typicallycharacterized as polyurethanes, while the products of reaction mixtureshaving an isocyanate index of 180 to 350 are typically characterized aspolyisocyanurates. Formation of isocyanurate groups is favored not onlyby high isocyanate indices, but also by use of catalysts forisocyanurate formation, such as N-hydroxyalkyl quaternary ammoniumcarboxylates.

In some embodiments, the polyurethane or polyisocyanurate foam is aproduct of a method comprising reacting a polyol and an isocyanatecompound in the presence of a blowing agent and a particulatepoly(phenylene ether) to form the polyurethane or polyisocyanurate foam,wherein the isocyanate compound comprises, on average, at least twoisocyanate groups per molecule. The polyol can comprise, on average, atleast two hydroxyl groups per molecule and often comprises three or morehydroxyl groups per molecule.

Polyols useful in the method include polyether polyols prepared byreacting an initiator containing 2 to 8 hydroxyl groups per molecule,specifically 3 to 8 hydroxyl groups per molecule, with an alkoxylatingagent such as ethylene oxide, propylene oxide, or butylene oxide.Specific examples of polyols include ethoxylated saccharides,propoxylated saccharides, butoxylated saccharides, ethoxylatedglycerins, propoxylated glycerins, butoxylated glycerins, ethoxylateddiethanolamines, propoxylated diethanolamines, butoxylateddiethanolamines, ethoxylated triethanolamines, propoxylatedtriethanolamines, butoxylated triethanolamines, ethoxylatedtrimethylolpropanes, propoxylated trimethylolpropanes, butoxylatedtrimethylolpropanes, ethoxylated erythritols, propoxylated erythritols,butoxylated erythritols, ethoxylated pentaerythritols, propoxylatedpentaerythritols, butoxylated pentaerythritols, and combinationsthereof. In some embodiments, the polyol is selected from propoxylatedsaccharides, propoxylated glycerins, propoxylated diethanolamines,propoxylated triethanolamines, propoxylated trimethylolpropanes,propoxylated erythritols, propoxylated pentaerythritols, andcombinations thereof. Polyols further include aliphatic polyester diols,aromatic polyester polyols, and combinations thereof. In someembodiments, the polyol comprises a propoxylated sucrose, a propoxylatedglycerin, an aromatic polyester diol, or a combination thereof.

Isocyanate compounds useful in the method include, for example,1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate,2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylenediisocyanate, cyclohexane-1,3-diisocyanate, andcyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanatomethylcyclopentane,1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl-cyclohexane,bis(4-isocyanatocyclohexyl)methane, 2,4′-dicyclohexyl-methanediisocyanate, 1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis-(isocyanatomethyl)-cyclohexane,bis(4-isocyanato-3-methyl-cyclohexyl)methane,alpha,alpha,alpha′,alpha′-tetramethyl-1,3-xylylene diisocyanate,alpha,alpha,alpha′,alpha′-tetramethyl-1,4-xylylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanatomethyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, 2,4-diphenylmethanediisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-diisocyanatonaphthalene, an oligomeric diphenylmethane diisocyanate having anaverage of greater than 2 and less than or equal to 4 isocyanate groupsper molecule, and combinations thereof. In some embodiments, theisocyanate compound comprises an oligomeric diphenylmethane diisocyanatehaving an average of greater than 2 and less than or equal to 4isocyanate groups per molecule.

Blowing agents useful in the method including physical blowing agents,chemical blowing agents, and combinations thereof. Physical blowingagents can be, for example, C₃-C₅ hydrofluoroalkanes and C₃-C₅hydrofluoroalkenes. The hydrofluoroalkane and hydrofluoroalkene blowingagents can also contain one or more hydrogen atoms and/or halogen atomsother than fluorine. In some embodiments, the hydrofluoroalkane andhydrofluoroalkene blowing agents have a boiling point of 10 to 40° C. at1 atmosphere. Specific physical blowing agents include1,1-difluoroethane, 1,1,1,2-tetrafluoroethane, pentafluoroethane,1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane,2-bromopentafluoropropene, 1-bromopentafluoropropene,3-bromopentafluoropropene, 3,4,4,5,5,5-heptafluoro-1-pentene,3-bromo-1,1,3,3-tetrafluoropropene, 2-bromo-1,3,3,3-tetrafluoropropene,1-bromo-2,3,3,3-tetrafluoropropene, 1,1,2,3,3,4,4-heptafluorobut-1-ene,2-bromo-3,3,3-trifluoropropene, E-1-bromo-3,3,3-trifluoropropene-1,(Z)-1,1,1,4,4,4-hexafluoro-2-butene,3,3,3-trifluoro-2-(trifluoromethyl)propene,1-chloro-3,3,3-trifluoropropene, 2-chloro-3,3,3-trifluoropropene,1,1,1-trifluoro-2-butene, and combinations thereof. The physical blowingagent, when used, may be present at 2 to 20 weight percent, based on thetotal weight of the reaction mixture. Within this range, the physicalblowing agent amount can be 2.5 to 15 weight percent.

Chemical blowing agents include water and carboxylic acids that reactionwith isocyanate groups to liberate carbon dioxide. When present,chemical blowing agents, and specifically water, can be used in anamount of 0.2 to 5 weight percent, based on the total weight of thereaction mixture. Within this range, the chemical blowing agent amountcan be 0.2 to 3 weight percent.

In addition to the polyol, the isocyanate compound, and the blowingagent, the reaction mixture can include additives such as, for example,catalysts, surfactants, fire retardants, smoke suppressants, fillersand/or reinforcements other than the particulate poly(phenylene ether),antioxidants, UV stabilizers, antistatic agents, infrared radiationabsorbers, viscosity reducing agents, pigments, dyes, mold releaseagents, antifungal agents, biocides, and combinations thereof.

Catalysts include urethane catalysts, isocyanurate catalysts, andcombinations thereof. Suitable catalysts include tertiary aminecatalysts such as dimethylcyclohexylamine, benzyldimethylamine,N,N,N′,N″,N″-pentamethyldiethylenetriamine,2,4,6-tris-(dimethylaminomethyl)-phenol, triethylenediamine,N,N-dimethyl ethanolamine, and combinations thereof, organometalliccompounds such as potassium octoate (2-ethyl hexanoate), potassiumacetate, dibutyltin dilaurate, dibutlytin diacetate, and combinationsthereof; quaternary ammonium salts such as 2-hydroxpropyltrimethylammonium formate; N-substituted triazines such asN,N′,N″-dimethylaminopropylhexahydrotriazine; and combinations thereof.

Suitable surfactants include, for example, polyorganosiloxanes,polyorganosiloxane polyether copolymers, phenol alkoxylates (such asethoxylated phenol), alkylphenol alkoxylates (such as ethoxylatednonylphenol), and combinations thereof. The surfactants can function asemulsifiers and/or foam stabilizers.

The particulate poly(phenylene ether) contributes to the flameretardancy of the foam. Flame retardancy is also promoted by the use ofaromatic polyester polyols, when employed, and isocyanurate groups, whenformed. One or more additional flame retardants can, optionally, beincluded in the reaction mixture. Such additional flame retardantsinclude, for example, organophosphorous compounds such as organicphosphates (including trialkyl phosphates such as triethyl phosphate andtris(2-chloropropyl)phosphate, and triaryl phosphates such as triphenylphosphate and diphenyl cresyl phosphate), phosphites (including trialkylphosphites, triaryl phosphites, and mixed alkyl-aryl phosphites),phosphonates (including diethyl ethyl phosphonate, dimethyl methylphosphonate), polyphosphates (including melamine polyphosphate, ammoniumpolyphosphates), polyphosphites, polyphosphonates, phosphinates(including aluminum tris(diethyl phosphinate); halogenated fireretardants such as tetrabromophthalate esters and chlorinated paraffins;metal hydroxides such as magnesium hydroxide, aluminum hydroxide, cobalthydroxide, and hydrates of the foregoing metal hydroxide; andcombinations thereof. The flame retatrdant can be a reactive typeflame-retardant (including polyols which contain phosphorus groups,10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phospha-phenanthrene-10-oxide,phosphorus-containing lactone-modified polyesters, ethylene glycolbis(diphenyl phosphate), neopentylglycol bis(diphenyl phosphate), amine-and hydroxyl-functionalized siloxane oligomers). These flame retardantscan be used alone or in conjunction with other flame retardants.

When present, additives are typically used in a total amount of 0.01 to30 weight percent, based on the total weight of the reaction mixture.Within this range, the total additive amount can be 0.02 to 10 weightpercent.

In a very specific embodiment of the polyurethane or polyisocyanuratefoam, the polyurethane or polyisocyanurate foam has a core density of0.02 to 0.06 grams/centimeter³ determined at 23° C. using ASTM D1622-03; the particulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether); the particulate poly(phenyleneether) has a mean particle size of 2 to 8 micrometers; the particulatepoly(phenylene ether) has a particle size distribution wherein 90percent of the particle volume distribution is in the range of 1 to 8micrometers; the polyurethane or polyisocyanurate foam comprises 5 to 30weight percent of the particulate poly(phenylene ether); thepolyurethane or polyisocyanurate foam is a product of a methodcomprising reacting a polyol and an isocyanate compound in the presenceof a blowing agent and a particulate poly(phenylene ether) to form thepolyurethane or polyisocyanurate foam, wherein the isocyanate compoundcomprises, on average, at least two isocyanate groups per molecule; thepolyol comprises a wherein the polyol comprises a propoxylated sucrose,a propoxylated glycerin, an aromatic polyester diol, or a combinationthereof; and the isocyanate compound comprises an oligomericdiphenylmethane diisocyanate having an average of greater than 2 andless than or equal to 4 isocyanate groups per molecule.

The polyurethane or polyisocyanurate foam is particularly useful as athermal insulation material. Thus, one embodiment is an articlecomprising thermal insulation comprising polyurethane orpolyisocyanurate foam comprising 1 to 50 weight percent, based on thetotal weight of the polyurethane or polyisocyanurate foam, of aparticulate poly(phenylene ether) having a mean particle size of 1 to 40micrometers; wherein the polyurethane or polyisocyanurate foam has acore density of 0.03 to 0.7 grams/centimeter³ determined at 23° C. usingASTM D 1622-03. All of the variations of the foam described above applyas well to the foam as a component of the article. Specific examples ofarticles that can utilize the polyurethane or polyisocyanurate foam as athermal insulation material include domestic appliances (such asdomestic and commercial refrigerators and freezers, and hot watertanks); building materials (such as wall and roofing panels, cut-to-sizepieces from slab stock, and spray-in-place foam for insulation andsealing); thermally insulated tanks and containers, pipelines, heatingpipes, cooling pipes, and cold stores; and thermally insulatedrefrigerated vehicles for road and rail including containers.

One embodiment is a method of forming a polyurethane or polyisocyanuratefoam, the method comprising: reacting a polyol and an isocyanatecompound in the presence of a blowing agent and a particulatepoly(phenylene ether) to form a polyurethane or polyisocyanurate foam;wherein the isocyanate compound comprises, on average, at least twoisocyanate groups per molecule; wherein the particulate poly(phenyleneether) has a mean particle size of 1 to 40 micrometers; and wherein thepolyurethane or polyisocyanurate foam comprises 1 to 50 weight percentof the particulate poly(phenylene ether). Polyols, isocyanate compounds,and blowing agents are described above in the context of theproduct-by-process embodiments of the foam. All variations of the foamand the process described above apply as well to the present method offorming a polyurethane or polyisocyanurate foam.

In some embodiments of the method, the polyol, the isocyanate compound,and water, if any, are present in amounts sufficient to provide anisocyanate index of 180 to 350.

To prepare the polyurethane or polyisocyanurate foam, the polyolcomponent and the isocyanate component, which have been temperaturecontrolled and provided with additives, are thoroughly mixed together.The reaction starts after a short period of time and progresses withheat development. The reaction mixture is continually expanded by theblowing gases released, until the reaction product reaches the solidstate as a result of progressive cross-linkage, the foam structure beingretained.

The following stages are characteristic of the reaction and foamingprocess.

-   -   The mix time indicates the time needed for mixing the reactants.    -   The cream time is the time which elapses from the start of        mixing of the reactants to the first definite appearance of foam        expansion. In many cases this can be seen clearly by a color        change as the reaction mixture begins to rise. With slow        reacting mixtures this requires practiced observation.    -   The gel time is the interval of time between mixing the        reactants and the formation of a non-flowing, semi-solid,        jelly-like system. It is the time when the foam has developed        enough gel strength to be dimensionally stable. After the gel        time, the speed at which the foam rises slows down.    -   The rise time is the time from the start of mixing until the end        of the optically perceptible rise. Hence it is the time until        foam expansion ceases. The surface of the foam is still tacky        when the rise process is complete.    -   The tack-free time is the time elapsing from the start of mixing        to the moment when the foam surface has cured sufficiently that        its surface is no longer tacky or sticky. The moment of freedom        from tack can be determined by repeatedly testing the foam        surface with a wooden rod.

In a specific embodiment of the method, the polyurethane orpolyisocyanurate foam has a core density of 0.02 to 0.06grams/centimeter³ determined at 23° C. using ASTM D 1622-03; theparticulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether); the particulate poly(phenyleneether) has a mean particle size of 2 to 8 micrometers; the particulatepoly(phenylene ether) has a particle size distribution wherein 90percent of the particle volume distribution is in the range of 1 to 8micrometers; the polyurethane or polyisocyanurate foam comprises 5 to 30weight percent of the particulate poly(phenylene ether); the polyolcomprises a propoxylated sucrose, a propoxylated glycerin, an aromaticpolyester diol, or a combination thereof; and the isocyanate compoundcomprises an oligomeric diphenylmethane diisocyanate having an averageof greater than 2 and less than or equal to 4 isocyanate groups permolecule.

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are independently combinable with each other. Each rangedisclosed herein constitutes a disclosure of any point or sub-rangelying within the disclosed range.

The invention includes at least the following embodiments.

Embodiment 1

A polyurethane or polyisocyanurate foam comprising 1 to 50 weightpercent, based on the total weight of the polyurethane orpolyisocyanurate foam, of a particulate poly(phenylene ether) having amean particle size of 1 to 40 micrometers; wherein the polyurethane orpolyisocyanurate foam has a core density of 0.03 to 0.7grams/centimeter³ determined at 23° C. using ASTM D 1622-03.

Embodiment 2

The polyurethane or polyisocyanurate foam of embodiment 1, having a coredensity of 0.03 to 0.06 grams/centimeter³ determined at 23° C. usingASTM D 1622-03.

Embodiment 3

The polyurethane or polyisocyanurate foam of embodiment 1 or 2, whereinthe polyurethane or polyisocyanurate foam is a polyurethane foam that isthe product of a process characterized by an isocyanate index of 105 to125.

Embodiment 4

The polyurethane or polyisocyanurate foam of embodiment 1 or 2, whereinthe polyurethane or polyisocyanurate foam is a polyisocyanurate foamthat is the product of a process characterized by an isocyanate index of180 to 350.

Embodiment 5

The polyurethane or polyisocyanurate foam of any of embodiments 1-4,wherein the particulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether).

Embodiment 6

The polyurethane or polyisocyanurate foam of any of embodiments 1-5,wherein the particulate poly(phenylene ether) has a mean particle sizeof 2 to 8 micrometers.

Embodiment 7

The polyurethane or polyisocyanurate foam of any of embodiments 1-6,wherein the particulate poly(phenylene ether) has a particle sizedistribution wherein 90 volume percent of the particle size distributionis in the range of 1 to 8 micrometers.

Embodiment 8

The polyurethane or polyisocyanurate foam of any of embodiments 1-7,comprising 5 to 30 weight percent of the particulate poly(phenyleneether).

Embodiment 9

The polyurethane or polyisocyanurate foam of any of embodiments 1-8,wherein the polyurethane or polyisocyanurate foam is a product of amethod comprising reacting a polyol and an isocyanate compound in thepresence of a blowing agent and a particulate poly(phenylene ether) toform the polyurethane or polyisocyanurate foam; wherein the isocyanatecompound comprises, on average, at least two isocyanate groups permolecule.

Embodiment 10

The polyurethane or polyisocyanurate foam of embodiment 9, wherein thepolyol comprises an ethoxylated saccharide, a propoxylated saccharide, abutoxylated saccharide, an ethoxylated glycerin, a propoxylatedglycerin, a butoxylated glycerin, an ethoxylated diethanolamine, apropoxylated diethanolamine, a butoxylated diethanolamine, anethoxylated triethanolamine, a propoxylated triethanolamine, abutoxylated triethanolamine, an ethoxylated trimethylolpropane, apropoxylated trimethylolpropane, a butoxylated trimethylolpropane, anethoxylated erythritol, a propoxylated erythritol, a butoxylatederythritol, an ethoxylated pentaerythritol, a propoxylatedpentaerythritol, a butoxylated pentaerythritol, an aliphatic polyesterdiol, an aromatic polyester polyol, or a combination thereof

Embodiment 11

The polyurethane or polyisocyanurate foam of embodiment 9, wherein thepolyol comprises a propoxylated sucrose, a propoxylated glycerin, anaromatic polyester diol, or a combination thereof

Embodiment 12

The polyurethane or polyisocyanurate foam of any of embodiments 9-11,wherein the isocyanate compound comprises 1,4-tetramethylenediisocyanate, 1,6-hexamethylene diisocyanate,2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylenediisocyanate, cyclohexane-1,3-diisocyanate, andcyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanatomethylcyclopentane,1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl-cyclohexane,bis(4-isocyanatocyclohexyl)methane, 2,4′-dicyclohexyl-methanediisocyanate, 1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis-(isocyanatomethyl)-cyclohexane,bis(4-isocyanato-3-methyl-cyclohexyl)methane,alpha,alpha,alpha′,alpha′-tetramethyl-1,3-xylylene diisocyanate,alpha,alpha,alpha′,alpha′-tetramethyl-1,4-xylylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanatomethyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, 2,4-diphenylmethanediisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-diisocyanatonaphthalene, an oligomeric diphenylmethane diisocyanate having anaverage of greater than 2 and less than or equal to 4 isocyanate groupsper molecule, or a combination thereof

Embodiment 13

The polyurethane or polyisocyanurate foam of any of embodiments 9-11,wherein the isocyanate compound comprises an oligomeric diphenylmethanediisocyanate having an average of greater than 2 and less than or equalto 4 isocyanate groups per molecule.

Embodiment 14

The polyurethane or polyisocyanurate foam of embodiment 1, wherein thepolyurethane or polyisocyanurate foam has a core density of 0.02 to 0.06grams/centimeter³ determined at 23° C. using ASTM D 1622-03; wherein theparticulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether); wherein the particulatepoly(phenylene ether) has a mean particle size of 2 to 8 micrometers;wherein the particulate poly(phenylene ether) has a particle sizedistribution wherein 90 percent of the particle volume distribution isin the range of 1 to 8 micrometers; wherein the polyurethane orpolyisocyanurate foam comprises 5 to 30 weight percent of theparticulate poly(phenylene ether); wherein the polyurethane orpolyisocyanurate foam is a product of a method comprising reacting apolyol and an isocyanate compound in the presence of a blowing agent anda particulate poly(phenylene ether) to form the polyurethane orpolyisocyanurate foam, wherein the isocyanate compound comprises, onaverage, at least two isocyanate groups per molecule; wherein the polyolcomprises a wherein the polyol comprises a propoxylated sucrose, apropoxylated glycerin, an aromatic polyester diol, or a combinationthereof; and wherein the isocyanate compound comprises an oligomericdiphenylmethane diisocyanate having an average of greater than 2 andless than or equal to 4 isocyanate groups per molecule.

Embodiment 14a

The polyurethane or polyisocyanurate foam of embodiment 14, wherein thepolyurethane or polyisocyanurate foam is a polyurethane foam that is theproduct of a process characterized by an isocyanate index of 105 to 125.

Embodiment 14b

The polyurethane or polyisocyanurate foam of embodiment 14, wherein thepolyurethane or polyisocyanurate foam is a polyisocyanurate foam that isthe product of a process characterized by an isocyanate index of 180 to350.

Embodiment 15

An article comprising thermal insulation comprising polyurethane orpolyisocyanurate foam comprising 1 to 50 weight percent, based on thetotal weight of the polyurethane or polyisocyanurate foam, of aparticulate poly(phenylene ether) having a mean particle size of 1 to 40micrometers; wherein the polyurethane or polyisocyanurate foam has acore density of 0.03 to 0.7 grams/centimeter³ determined at 23° C. usingASTM D 1622-03.

Embodiment 16

A method of forming a polyurethane or polyisocyanurate foam, the methodcomprising: reacting a polyol and an isocyanate compound in the presenceof a blowing agent and a particulate poly(phenylene ether) to form apolyurethane or polyisocyanurate foam; wherein the isocyanate compoundcomprises, on average, at least two isocyanate groups per molecule;wherein the particulate poly(phenylene ether) has a mean particle sizeof 1 to 40 micrometers; and wherein the polyurethane or polyisocyanuratefoam comprises 1 to 50 weight percent of the particulate poly(phenyleneether).

Embodiment 17

The method of embodiment 16, wherein the polyol, the isocyanatecompound, and water, if any, are present in amounts sufficient toprovide an isocyanate index of 180 to 350.

Embodiment 18

The method of embodiment 16, wherein the polyurethane orpolyisocyanurate foam has a core density of 0.02 to 0.06grams/centimeter³ determined at 23° C. using ASTM D 1622-03; wherein theparticulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether); wherein the particulatepoly(phenylene ether) has a mean particle size of 2 to 8 micrometers;wherein the particulate poly(phenylene ether) has a particle sizedistribution wherein 90 percent of the particle volume distribution isin the range of 1 to 8 micrometers; wherein the polyurethane orpolyisocyanurate foam comprises 5 to 30 weight percent of theparticulate poly(phenylene ether); wherein the polyol comprises apropoxylated sucrose, a propoxylated glycerin, an aromatic polyesterdiol, or a combination thereof; and wherein the isocyanate compoundcomprises an oligomeric diphenylmethane diisocyanate having an averageof greater than 2 and less than or equal to 4 isocyanate groups permolecule.

The invention is further illustrated by the following non-limitingexamples.

Examples 1-3, Comparative Example A

Raw materials used in the working examples are summarized in Table 1.

TABLE 1 Reagent Description POLY-G ™ 74-376 A mixture of propoxylatedsucrose (CAS Reg. No. 9049-71-2) and propoxylated glycerin (CAS Reg. No.25791-96-2), the mixture having an OH number of 368 milligrams KOH/gramand a viscosity of 2700 centipoise at 25° C.; available as POLY-G ™74-376 from Arch Chemicals, Inc. TERATE ™ 4026 An aromatic polyesterpolyol having an OH number of 200 milligrams/gram, a viscosity of 2500centipoise at 25° C., a number average molecular weight of about 560grams/mole, and about 2 hydroxyl groups per molecule; available asTERATE ™ 4026 from Invista. RUBINATE ™ M An oligomeric diphenylmethanediisocyanate having 31.0 weight percent isocyanate groups and an averageof 2.7 isocyanate groups per molecule; available as RUBINATE ™ M fromHuntsman. DABCO ™ 33LV 33 weight percent triethylenediamine indipropylene glycol; available as DABCO ™ 33LV from Air Products. NIAX ™A-1 70 weight percent bis(dimethylaminoethyl)ether in dipropyleneglycol; available as NIAX ™ A-1 from Momentive. DABCO ™ TMR-4 AnN-hydroxyalkyl quaternary ammonium carboxylate (catalyst for formationof isocyanurate groups) having an OH number of 687 milligrams OH/gramand a viscosity of 34 centipoise at 25° C.; available as DABCO ™ TMR-4from Air Products. POLYCAT ™ 8 N,N-dimethylcyclohexylamine; available asPOLYCAT ™ 8 from Air Products. DABCO ™ DC193 A polysiloxane surfactant;available as DABCO ™ DC193 from Air Products. ENOVATE ™ 30001,1,1,3,3-pentafluropropane (HFC-245fa); available as ENOVATE ™ 3000from Honeywell Particulate PPE Poly(2,6-dimethyl-1,4-phenylene ether)particles having a mean particle size of 6.1 micrometers, 10 volumepercent of particles less than 4.0 micrometers, 10 volume percent ofparticles greater than 8.1 micrometers, and a mean aspect ratio of1.41:1.

Particulate poly(2,6-dimethyl-1,4-phenylene ether) was obtained by jetmilling commercial grade poly(phenylene ether) powder obtained as PPO™640 resin from Sabic Innovative Plastics. Compressed nitrogen gas wasintroduced into the nozzles of a jet mill to create a supersonicgrinding stream. Particle-on-particle impact collisions in this grindingstream resulted in substantial particle size reductions. Large particleswere held in the grinding area by centrifugal force while centripetalforce drove finer particles toward the center of the discharge. A sieveof a specific upper size limit was then used in-line to recoverparticles with a precise size distribution and having diameters belowthe nominal sieve openings. Larger particles were recycled to thereduction size chamber for further grinding. The particulatepoly(2,6-dimethyl-1,4-phenylene ether) was classified by passing thejet-milled particles through a screen with 6 micrometer openings. Theparticle size and shape characterization in Table 1 was determined usinga CAMSIZER™ XT from Retsch Technology GmbH operating in air dispersionmode.

Rigid foams were prepared using a high-torque mixer (CRAFTSMAN Ten InchDrill Press, Model No. 137.219000) at 3,100 rotations per minute. Polyolcomponents and isocyanate components of the foam systems were mixed for10 seconds. The resulting mixture was transferred into an open cake boxbefore the cream time and allowed to free-rise. Foaming profile,including cream time, gel time, rise time, and tack-free time wasdetermined on all foams.

All foams were cut and tested after aging at ambient conditions for oneweek. The following methods were used for testing of rigid foams. Coredensity values, expressed in grams/centimeter³, were determined at 23°C. using ASTM D 1622-03 and a sample size of 5.08 centimeters×5.08centimeters×2.54 centimeters (2 inches×2 inches×1 inch). Compressivestrength values, expressed in megapascals, were determined at 23° C.using ASTM D 1621-00 and a sample size of 5.08 centimeters×5.08centimeters×2.54 centimeters (2 inches×2 inches×1 inch) and a head speedof 2.5 millimeters/minute. Values of burning rate in a horizontalposition, expressed in millimeters/minute, were determined according toASTM D635-03 using a sample size of 15.24 centimeters×5.08centimeters×1.27 centimeters (6 inches×2 inches×0.5 inch). Waterabsorption values, expressed in percent, were determined according toASTM D 2842-01 using a sample size of 5.08 centimeters×5.08centimeters×2.54 centimeters (2 inches×2 inches×1 inch), and immersionin water for 96 and 168 hours at 25° C. and 1 atmosphere.

Table 2 summarizes examples in which the particulate poly(phenyleneether) was added only to the polyol component of the polyurethaneformulation. The property results show that similar core densities wereobtained for each foam, but, relative to Comparative Example A,inventive Examples 1-3 exhibited higher compressive strength values.

TABLE 2 C. Ex. A Ex. 1 Ex. 2 Ex. 3 COMPOSITION Polyol Component POLY-G ™74-376 100 90 80 70 Particulate PPE 0 10 20 30 Water 4.5 4.5 4.5 4.5DABCO ™ DC193 2.5 2.5 2.5 2.5 DABCO ™ 33LV 0.6 0.6 0.6 0.6 IsocyanateComponent RUBINATE ™ M 173.62 163.85 154.07 144.3 PROCESS IsocyanateIndex 110 110 110 110 PPE content (wt %) 0 3.68 7.64 11.91 ReactionProfile of Free-rise No. of foaming 2 1 1 1 experiments Mix time (sec)10 10 10 10 Cream time (sec) 68 68 50 45 Gel time (sec) 290 145 133 120Rise time (sec) 820 380 360 290 Tack-free time (sec) 1230 990 690 540PROPERTIES Core density (g/cc) 0.04101 0.04149 0.04197 0.04261Compressive Strength 0.1296 0.1859 0.1826 0.1882 at Yield (MPa)

Examples 4-6, Comparative Example B

In order to maximize the amount of the particulate poly(phenylene ether)in the polyurethane foam system, the particulate poly(phenylene ether)was added through both the polyol component and the isocyanate componentof the foam systems. Compositions, processes, and properties aresummarized in Table 3. The property results show that, relative toComparative Example B, inventive Examples 4-6 with particulatepoly(phenylene ether) exhibited reduced flammability and reduced waterabsorption.

TABLE 3 C. Ex. B Ex. 4 Ex. 5 Ex. 6 COMPOSITION Polyol Component POLY-G ™74-376 100 85 80 75 Particulate PPE 0 44.9 61.2 78.2 Water 4.5 4.5 4.54.5 DABCO ™ DC193 2 2 2 2 DABCO ™ 33LV 1.8 1.8 1.8 1.8 NIAX ™ A-1 0.10.1 0.1 0.1 Isocyanate Component RUBINATE ™ M 175.29 160.63 155.74150.85 PROCESS PPE content (wt %) 0 15 20 25 Mode of particulate PPEaddition: Polyol Component (pbw) 0 27.76 26.12 24.5 Isocyanate Component0 17.14 35.08 53.7 (pbw) Isocyanate Index 110 110 110 110 ReactionProfile of Free-rise No. of foaming 4 3 3 3 experiments Mix time (sec) 77 7 7 Cream time (sec) 13 13 13 12 Gel time (sec) 63 58 51 48 Rise time(sec) 95 98 93 85 Tack-free time (sec) 105 115 110 100 PROPERTIES Coredensity (g/cc) 0.03396 0.03829 0.04133 0.04037 Compressive Strength0.1646 0.2206 0.2023 0.1287 at Yield (MPa) Flammability - 31.06 24.423.9 21.35 Burn Rate (cm/min) Water Absorption at 25° C. % change after96 hours 230 — — 126 % change after 168 hours 239 — — 153

Examples 7-9, Comparative Example C

Examples of polyisocyanurate foam systems are summarized in Table 4. Theparticulate poly(phenylene ether) was added through the both polyolcomponent and isocyanate component of the foam systems. The propertyresults show that, relative to Comparative Example C, inventive Examples7-9 with particulate poly(phenylene ether) exhibited reducedflammability and reduced water absorption.

TABLE 4 C. Ex. C Ex. 7 Ex. 8 Ex. 9 COMPOSITION Polyol Component POLY-G ™74-376 50 45 42.5 40 TERATE ™ 4026 50 45 42.5 40 Particulate PPE 0 33.2538.25 68 Water 1 1 1 1 DABCO ™ DC193 1.4 1.4 1.4 1.4 POLYCAT ™ 8 0.4 0.40.4 0.4 DABCO ™ TMR-4 2.1 2.1 2.1 2.1 ENOVATE ™ 3000 25 25 30 30Isocyanate Component RUBINATE ™ M 192.23 177.1 169.6 162.05 PROCESS PPEcontent (wt %) 0 10 15 20 Mode of particulate PPE addition: PolyolComponent (pbw) 0 27 25.5 24 Isocyanate Component 0 6.25 13.5 44 (pbw)Isocyanate Index 220 220 220 220 Reaction Profile of Free-rise No. offoaming 3 2 2 2 experiments Mix time (sec) 7 7 7 7 Cream time (sec) 1514 13 13 Gel time (sec) 70 58 53 47 Rise time (sec) 149 156 157 138Tack-free time (sec) 260 256 235 255 PROPERTIES Core density (g/cc)0.03268 0.03380 0.03252 0.03460 Compressive Strength 0.1648 0.13360.1166 0.1055 at Yield (MPa) Flammability - 33.1 27.18 28.87 21.61 BurnRate (cm/min) Water Absorption at 25° C. % change after 96 hours 237 — —153 % change after 168 hours 239 — — 173

1. A polyurethane or polyisocyanurate foam comprising 1 to 50 weightpercent, based on the total weight of the polyurethane orpolyisocyanurate foam, of a particulate poly(phenylene ether) having amean particle size of 1 to 40 micrometers; wherein the polyurethane orpolyisocyanurate foam has a core density of 0.03 to 0.7grams/centimeter³ determined at 23° C. using ASTM D 1622-03.
 2. Thepolyurethane or polyisocyanurate foam of claim 1, having a core densityof 0.03 to 0.06 grams/centimeter³ determined at 23° C. using ASTM D1622-03.
 3. The polyurethane or polyisocyanurate foam of claim 1,wherein the polyurethane or polyisocyanurate foam is a polyurethane foamthat is the product of a process characterized by an isocyanate index of105 to
 125. 4. The polyurethane or polyisocyanurate foam of claim 1,wherein the polyurethane or polyisocyanurate foam is a polyisocyanuratefoam that is the product of a process characterized by an isocyanateindex of 180 to
 350. 5. The polyurethane or polyisocyanurate foam ofclaim 1, wherein the particulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether).
 6. The polyurethane orpolyisocyanurate foam of claim 1, wherein the particulate poly(phenyleneether) has a mean particle size of 2 to 8 micrometers.
 7. Thepolyurethane or polyisocyanurate foam of claim 1, wherein theparticulate poly(phenylene ether) has a particle size distributionwherein 90 volume percent of the particle size distribution is in therange of 1 to 8 micrometers.
 8. The polyurethane or polyisocyanuratefoam of claim 1, comprising 5 to 30 weight percent of the particulatepoly(phenylene ether).
 9. The polyurethane or polyisocyanurate foam ofclaim 1, wherein the polyurethane or polyisocyanurate foam is a productof a method comprising reacting a polyol and an isocyanate compound inthe presence of a blowing agent and a particulate poly(phenylene ether)to form the polyurethane or polyisocyanurate foam; wherein theisocyanate compound comprises, on average, at least two isocyanategroups per molecule.
 10. The polyurethane or polyisocyanurate foam ofclaim 9, wherein the polyol comprises an ethoxylated saccharide, apropoxylated saccharide, a butoxylated saccharide, an ethoxylatedglycerin, a propoxylated glycerin, a butoxylated glycerin, anethoxylated diethanolamine, a propoxylated diethanolamine, a butoxylateddiethanolamine, an ethoxylated triethanolamine, a propoxylatedtriethanolamine, a butoxylated triethanolamine, an ethoxylatedtrimethylolpropane, a propoxylated trimethylolpropane, a butoxylatedtrimethylolpropane, an ethoxylated erythritol, a propoxylatederythritol, a butoxylated erythritol, an ethoxylated pentaerythritol, apropoxylated pentaerythritol, a butoxylated pentaerythritol, analiphatic polyester diol, an aromatic polyester polyol, or a combinationthereof.
 11. The polyurethane or polyisocyanurate foam of claim 9,wherein the polyol comprises a propoxylated sucrose, a propoxylatedglycerin, an aromatic polyester diol, or a combination thereof.
 12. Thepolyurethane or polyisocyanurate foam of claim 9, wherein the isocyanatecompound comprises 1,4-tetramethylene diisocyanate, 1,6-hexamethylenediisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate,1,12-dodecamethylene diisocyanate, cyclohexane-1,3-diisocyanate, andcyclohexane-1,4-diisocyanate, 1-isocyanato-2-isocyanatomethylcyclopentane,1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl-cyclohexane,bis(4-isocyanatocyclohexyl)methane, 2,4′-dicyclohexyl-methanediisocyanate, 1,3-bis(isocyanatomethyl)-cyclohexane,1,4-bis-(isocyanatomethyl)-cyclohexane,bis(4-isocyanato-3-methyl-cyclohexyl)methane,alpha,alpha,alpha′,alpha′-tetramethyl-1,3-xylylene diisocyanate,alpha,alpha,alpha′,alpha′-tetramethyl-1,4-xylylene diisocyanate,1-isocyanato-1-methyl-4(3)-isocyanatomethyl cyclohexane,2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate,1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, 2,4-diphenylmethanediisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-diisocyanatonaphthalene, an oligomeric diphenylmethane diisocyanate having anaverage of greater than 2 and less than or equal to 4 isocyanate groupsper molecule, or a combination thereof.
 13. The polyurethane orpolyisocyanurate foam of claim 9, wherein the isocyanate compoundcomprises an oligomeric diphenylmethane diisocyanate having an averageof greater than 2 and less than or equal to 4 isocyanate groups permolecule.
 14. The polyurethane or polyisocyanurate foam of claim 1,wherein the polyurethane or polyisocyanurate foam has a core density of0.02 to 0.06 grams/centimeter³ determined at 23° C. using ASTM D1622-03; wherein the particulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether); wherein the particulatepoly(phenylene ether) has a mean particle size of 2 to 8 micrometers;wherein the particulate poly(phenylene ether) has a particle sizedistribution wherein 90 percent of the particle volume distribution isin the range of 1 to 8 micrometers; wherein the polyurethane orpolyisocyanurate foam comprises 5 to 30 weight percent of theparticulate poly(phenylene ether); wherein the polyurethane orpolyisocyanurate foam is a product of a method comprising reacting apolyol and an isocyanate compound in the presence of a blowing agent anda particulate poly(phenylene ether) to form the polyurethane orpolyisocyanurate foam, wherein the isocyanate compound comprises, onaverage, at least two isocyanate groups per molecule; wherein the polyolcomprises a wherein the polyol comprises a propoxylated sucrose, apropoxylated glycerin, an aromatic polyester diol, or a combinationthereof; and wherein the isocyanate compound comprises an oligomericdiphenylmethane diisocyanate having an average of greater than 2 andless than or equal to 4 isocyanate groups per molecule.
 15. An articlecomprising thermal insulation comprising polyurethane orpolyisocyanurate foam comprising 1 to 50 weight percent, based on thetotal weight of the polyurethane or polyisocyanurate foam, of aparticulate poly(phenylene ether) having a mean particle size of 1 to 40micrometers; wherein the polyurethane or polyisocyanurate foam has acore density of 0.03 to 0.7 grams/centimeter³ determined at 23° C. usingASTM D 1622-03.
 16. A method of forming a polyurethane orpolyisocyanurate foam, the method comprising: reacting a polyol and anisocyanate compound in the presence of a blowing agent and a particulatepoly(phenylene ether) to form a polyurethane or polyisocyanurate foam;wherein the isocyanate compound comprises, on average, at least twoisocyanate groups per molecule; wherein the particulate poly(phenyleneether) has a mean particle size of 1 to 40 micrometers; and wherein thepolyurethane or polyisocyanurate foam comprises 1 to 50 weight percentof the particulate poly(phenylene ether).
 17. The method of claim 16,wherein the polyol, the isocyanate compound, and water, if any, arepresent in amounts sufficient to provide an isocyanate index of 180 to350.
 18. The method of claim 16, wherein the polyurethane orpolyisocyanurate foam has a core density of 0.02 to 0.06grams/centimeter³ determined at 23° C. using ASTM D 1622-03; wherein theparticulate poly(phenylene ether) is a particulatepoly(2,6-dimethyl-1,4-phenylene ether); wherein the particulatepoly(phenylene ether) has a mean particle size of 2 to 8 micrometers;wherein the particulate poly(phenylene ether) has a particle sizedistribution wherein 90 percent of the particle volume distribution isin the range of 1 to 8 micrometers; wherein the polyurethane orpolyisocyanurate foam comprises 5 to 30 weight percent of theparticulate poly(phenylene ether); wherein the polyol comprises apropoxylated sucrose, a propoxylated glycerin, an aromatic polyesterdiol, or a combination thereof, and wherein the isocyanate compoundcomprises an oligomeric diphenylmethane diisocyanate having an averageof greater than 2 and less than or equal to 4 isocyanate groups permolecule.